def __init__(self, width):
self.width = width
- self.in_z = FPNumBase(width, False)
- self.in_of = Overflow()
- self.out_z = FPNumBase(width, False)
- self.out_of = Overflow()
+ self.i = self.ispec()
+ self.o = self.ispec()
+
+ def ispec(self):
+ return FPAddStage1Data(self.width)
+
+ def ospec(self):
+ return FPAddStage1Data(self.width)
def setup(self, m, in_z, in_of, out_z):
""" links module to inputs and outputs
"""
m.submodules.normalise_1 = self
- m.d.comb += self.in_z.eq(in_z)
- m.d.comb += self.in_of.eq(in_of)
+ m.d.comb += self.i.z.eq(in_z)
+ m.d.comb += self.i.of.eq(in_of)
- m.d.comb += out_z.eq(self.out_z)
+ m.d.comb += out_z.eq(self.o.z)
def elaborate(self, platform):
m = Module()
- mwid = self.out_z.m_width+2
+ mwid = self.o.z.m_width+2
pe = PriorityEncoder(mwid)
m.submodules.norm_pe = pe
- m.submodules.norm1_out_z = self.out_z
- m.submodules.norm1_out_overflow = self.out_of
- m.submodules.norm1_in_z = self.in_z
- m.submodules.norm1_in_overflow = self.in_of
+ m.submodules.norm1_out_z = self.o.z
+ m.submodules.norm1_out_overflow = self.o.of
+ m.submodules.norm1_in_z = self.i.z
+ m.submodules.norm1_in_overflow = self.i.of
- in_z = FPNumBase(self.width, False)
- in_of = Overflow()
- m.submodules.norm1_insel_z = in_z
- m.submodules.norm1_insel_overflow = in_of
+ i = self.ispec()
+ m.submodules.norm1_insel_z = i.z
+ m.submodules.norm1_insel_overflow = i.of
- espec = (len(in_z.e), True)
+ espec = (len(i.z.e), True)
ediff_n126 = Signal(espec, reset_less=True)
msr = MultiShiftRMerge(mwid, espec)
m.submodules.multishift_r = msr
- m.d.comb += in_z.eq(self.in_z)
- m.d.comb += in_of.eq(self.in_of)
+ m.d.comb += i.eq(self.i)
# initialise out from in (overridden below)
- m.d.comb += self.out_z.eq(in_z)
- m.d.comb += self.out_of.eq(in_of)
+ m.d.comb += self.o.eq(i)
# normalisation increase/decrease conditions
decrease = Signal(reset_less=True)
increase = Signal(reset_less=True)
- m.d.comb += decrease.eq(in_z.m_msbzero & in_z.exp_gt_n126)
- m.d.comb += increase.eq(in_z.exp_lt_n126)
+ m.d.comb += decrease.eq(i.z.m_msbzero & i.z.exp_gt_n126)
+ m.d.comb += increase.eq(i.z.exp_lt_n126)
# decrease exponent
with m.If(decrease):
# *sigh* not entirely obvious: count leading zeros (clz)
# we reverse the order of the bits.
temp_m = Signal(mwid, reset_less=True)
temp_s = Signal(mwid+1, reset_less=True)
- clz = Signal((len(in_z.e), True), reset_less=True)
+ clz = Signal((len(i.z.e), True), reset_less=True)
# make sure that the amount to decrease by does NOT
# go below the minimum non-INF/NaN exponent
- limclz = Mux(in_z.exp_sub_n126 > pe.o, pe.o,
- in_z.exp_sub_n126)
+ limclz = Mux(i.z.exp_sub_n126 > pe.o, pe.o,
+ i.z.exp_sub_n126)
m.d.comb += [
# cat round and guard bits back into the mantissa
- temp_m.eq(Cat(in_of.round_bit, in_of.guard, in_z.m)),
+ temp_m.eq(Cat(i.of.round_bit, i.of.guard, i.z.m)),
pe.i.eq(temp_m[::-1]), # inverted
clz.eq(limclz), # count zeros from MSB down
temp_s.eq(temp_m << clz), # shift mantissa UP
- self.out_z.e.eq(in_z.e - clz), # DECREASE exponent
- self.out_z.m.eq(temp_s[2:]), # exclude bits 0&1
- self.out_of.m0.eq(temp_s[2]), # copy of mantissa[0]
+ self.o.z.e.eq(i.z.e - clz), # DECREASE exponent
+ self.o.z.m.eq(temp_s[2:]), # exclude bits 0&1
+ self.o.of.m0.eq(temp_s[2]), # copy of mantissa[0]
# overflow in bits 0..1: got shifted too (leave sticky)
- self.out_of.guard.eq(temp_s[1]), # guard
- self.out_of.round_bit.eq(temp_s[0]), # round
+ self.o.of.guard.eq(temp_s[1]), # guard
+ self.o.of.round_bit.eq(temp_s[0]), # round
]
# increase exponent
with m.Elif(increase):
temp_m = Signal(mwid+1, reset_less=True)
m.d.comb += [
- temp_m.eq(Cat(in_of.sticky, in_of.round_bit, in_of.guard,
- in_z.m)),
- ediff_n126.eq(in_z.N126 - in_z.e),
+ temp_m.eq(Cat(i.of.sticky, i.of.round_bit, i.of.guard,
+ i.z.m)),
+ ediff_n126.eq(i.z.N126 - i.z.e),
# connect multi-shifter to inp/out mantissa (and ediff)
msr.inp.eq(temp_m),
msr.diff.eq(ediff_n126),
- self.out_z.m.eq(msr.m[3:]),
- self.out_of.m0.eq(temp_s[3]), # copy of mantissa[0]
+ self.o.z.m.eq(msr.m[3:]),
+ self.o.of.m0.eq(temp_s[3]), # copy of mantissa[0]
# overflow in bits 0..1: got shifted too (leave sticky)
- self.out_of.guard.eq(temp_s[2]), # guard
- self.out_of.round_bit.eq(temp_s[1]), # round
- self.out_of.sticky.eq(temp_s[0]), # sticky
- self.out_z.e.eq(in_z.e + ediff_n126),
+ self.o.of.guard.eq(temp_s[2]), # guard
+ self.o.of.round_bit.eq(temp_s[1]), # round
+ self.o.of.sticky.eq(temp_s[0]), # sticky
+ self.o.z.e.eq(i.z.e + ediff_n126),
]
return m
rmod = FPRoundMod(self.width)
r_out_z = FPNumBase(self.width)
rmod.setup(m, n_out_z, n_out_roundz)
- m.d.comb += n_out_roundz.eq(nmod.out_of.roundz)
+ m.d.comb += n_out_roundz.eq(nmod.o.of.roundz)
m.d.comb += r_out_z.eq(rmod.out_z)
# Corrections (chained to rounding)